This invention relates to a base pan for an air conditioning unit and, in particular, to a base pan for a packaged terminal air conditioner (PTAC).
The present invention involves a base pan that is ideally suited for use in association with a packaged terminal air conditioner of the type generally used in hotels and motels or similar places of lodging where the air conditioning unit services a specific indoor comfort area such as a room to provide both heating and cooling. The PTAC unit is generally contained within a rectangular shaped sleeve that is mounted within an outside wall of the building in which the comfort area being serviced is housed. The unit typically includes an outdoor section and an indoor section that are separated by a dividing wall. Each section includes a heat exchanger and a fan for moving air over the heat exchanger surfaces.
It is common within the industry to utilize condensate produced by an indoor heat exchanger to cool the outdoor heat exchanger when the unit is operated in the cooling mode. This concept is more fully described in U.S. Pat. No. 6,067,812 that issued in the name of Bushnell et al. As described in the noted patent, the condensate from the indoor heat exchanger which is functioning as an evaporator in the cooling mode is collected in the base pan and is fed via gravity to an area beneath the outdoor fan which is now functioning as a condenser. The outdoor fan is equipped with a slinger ring that is arranged to pass through the condensate and distribute it over the outdoor heat exchanger to cool the heat exchanger surfaces thereby increasing the efficiency of the unit. This method of increasing the efficiency of a unit works well in practice, however, it takes a good deal of time after start up to provide sufficient condensate to the outdoor fan to begin the cooling process.
In U.S. Pat. No. 6,085,539 there is described a base pan for use in a PTAC unit that is designed to route condensate from the indoor heat exchanger to the outdoor fan. A condenser pan is removably mounted inside the base pan beneath the indoor heat exchanger. The base pan and the condenser pan have a number of tiers that allow the condensate from the indoor heat exchanger to cascade downwardly into a low collection region in the base pan beneath the outdoor heat exchanger. The collection region is thus relatively large and accordingly, a good deal of condensate must be collected before the outdoor fan can effectively distribute the condensate over the surfaces of the outdoor heat exchanger. The floor contours of the two metal pans are also relatively complex and thus relatively difficult to form as well as adding additional weight to the system.
It is therefore an object of the present invention to improve air conditioning systems and, in particular, packaged terminal air conditioning systems.
It is a further object of the present invention to provide a condensate control system for delivering condensate to the outdoor section of a PTAC unit shortly after the unit is placed in a cooling mode.
A still further object of the present invention is to provide a two piece base pan for an air conditioner that is relatively light weight and more easily formed when compared to similar base pans known in the prior art.
Another object of the present invention is to provide a light-weight auxiliary pan that is insertable into the base pan of an air conditioner unit that plays a part in the efficient distribution of comfort air as it is being discharged from the unit.
These and other objects of the current invention are attained in an air conditioning unit that contains an indoor section and an outdoor section that are separated by a dividing wall. Each section includes a heat exchanger and a fan for moving air over the surfaces of the heat exchanger. The unit further includes a base pan that has a floor and four raised side walls integral with the floor that encircle the unit. The floor of the base pan slants inwardly toward a reservoir area immediately adjacent to the indoor fan so that condensate collected in the reservoir is immediately available for use in cooling the outdoor heat exchanger. An auxiliary pan molded of light weight styrene is mounted inside the base pan beneath the indoor heat exchanger. The auxiliary pan contains a trough having an inside surface contour that forms a section of a shroud that surrounds the indoor fan.